Transistorized electronic percussion generator with organ



Sept' 5, 1967 H. o. SCHWARTZ ETAL 3,340,344

TRANSISTORIZED ELECTRONIC PECUSSION GENERATOR WITH ORGAN 2 Sheets-Sheetl Filed April l5, 1965 anni 4/ m 5 ww n EW R C R D Mm @JM m Wm LGMl/H MWN Ma me uw M w1 G w v or www D M m w MK E RHMH w .+4K E 5 R 0 P L sww s6 Pu n @P E 7 n ww MEM/ mm m w y l M C@ R A EE 5m d 6V w/m 5H 5 0 .R v.p E s E El/.H 5 Mm Z w wm m C@ Sept 5, 1957 H. o. SCHWARTZ ETAL3,340,344

TRANSISTORIZED ELECTRONIC PERCUSSION GENERATOR WITH ORGAN 2 Sheets-Sheet2 Filed April l5, 1965 NN www. um@ NN www mh NWN.

United States Patent O 3,340,344 TRANSISTORIZED ELECTRONIC PERCUSSIONGENERATOR WITH ORGAN Harold O. Schwartz, North Tonawanda, and Peter E.Maher, Tonawanda, N.Y., assignors to The Wurlitzer Company, Chicago,Ill., a corporation of Ohio Filed Apr. 15, 1965, Ser. No. 448,362Claims. (Cl. 84-1.24)

This invention relates 'to an electronic musical instrument, and moreparticularly to an electronic organ having rhythm percussiveaccompanying effects.

ln various locations, it is common practice to provide small dance bandsor musical combinations for producing or playing popular music fordancing or for entertainment. Generally speaking one or more instrumentsmay be used to produce the melody. In addition, there preferably is arhythm accompaniment, produced by one or more musicians operating withvarious percussive type sound generators, such as drums, blocks,brushes, cymbals, and the like. Such rhythm accompaniment is of arepetitive nature, differing in accordance with the nature of the music,i.e., fox trot, samba, cha cha, etc.

Often in a small club or public place of entertainment the financialexpense of a small orchestra is prohibitive. In order to make dancingpossible, or simply to provide background music, a single musician maybe hired to play an electronic organ or other melody instrument. Rhythmaccompaniment can be produced by an electronic rhythm device sold by theWurlitzer Cornpany and known as the Sideman This device is disclosed andclaimed in application for United States Letters Patent by Joseph H.Hearne, entitled Rhythm Device, S.N. 96,135, filed Mar. 16, 1961, andalso in the application of Joseph H. Hearne, Howard E. Holman, andMarvin C. Korinke, entitled Rhythm Device, S.N. 103,001, filed Apr. 14,1961. Although the Sideman rhythm device does produce excellent resultsand is eX- tremely versatile, it does entail the use of an additionalpiece of equipment, which in some instances may be undesirable. It alsorequires that the organist conform his timing to that of the rhythmdevice.

It therefore is an object of the present invention to provide atransistorized electronic organ with built-in transistorized rhythmaccompaniment.

Furthermore, it is an object of this invention to provide an improved,transistorized cymbal tone generator.

Other and further objects and advantages of the present invention willbe apparent from the following description when taken in connection withthe accompanying drawings wherein:

FIG. 1 is a perspective view of an electronic organ constructed inaccordance with the principles of the present invention;

FIG. 2 is a block wiring diagram illustrating the principles of theinvention; and

FIG. 3 is a schematic wiringdiagram of the electronic portions of therhythm accompaniment device.

Referring now in greater particularity to the drawings, and first toFIG. 1, there will be seen an electronic organ 10 constructed inaccordance with the principles of the present invention and includingthe usual housing or case 12 with a music rack 14 upstanding therefrom.The organ is provided with a lower manual or keyboard 16, and with anupper manual or keyboard 18, and also with a pedal board or clavier 20.There is a plurality of stop tablets 22, and a swell pedal 24 forcontrolling the over-all volume. A plurality of loudspeakers is providedbehind a grill 26.

The electronic aspects of the organ are shown schematically in FIG. 2.There is a plurality of key switches 28 respectively operated by thekeys of the manuals 16 "and a capacitor 70 in and 18. The key switchesare connected to a pulse producer 30 which can be activated to produce apulse each time a key is depressed. The pulses are connected asindicated to upper manual brush keying and to lower manual brush keying.

. The key switches also are connected to tone generators 32, and theseare connected in turn to filters and stops 34, an amplifier 36, and theloudspeakers 38 disposed behind the grill 26.

In addition, the tone generators 32 in the lower frequency range areconnected through a plurality of resistors 40 to pedal switches 42respectively operated by the pedals of the clavier 20. The fixedcontacts of the switches 42 are connected to a pedal amplifier 44, andthis in turn is connected to a first divider 46, the latter beingconnected to a second divider 48. The two dividers 46 and 48 areconnected to the filters and stops 34 for determining the footage atwhich the pedals will play.

There is also provided a plurality of rhythm generators 50, and theserhythm generators also are connected to the filters and stops 34.

Means is provided associated with the pedal switches 42 to providekeying for certain of the rhythm .generators, specifically the drums andcymbals. `In the illustrative example, there is a bail 52 disposed fordepression on closing of any of the pedal switches 42, a spring 53normally holding the bail 52 in rest or raised position. The bail has apair of switches connected to it in suitable insulated fashion, such asthe bail itself being an insulating material, or by means of insulatingpivots. One of the bail switches comprises a movable contact 54 which isgrounded, and which is engageable with a fixed contact 56 connected tothe cymbal keying. Another bail switch comprises a movable contact 58which is connected to a resistor 60. This resistor is connected at ajunction 62 to a resistor 64 leading to a positive potential, such as160 volts. The junction 62 is connected to the drum keying, asindicated.

The second bail switch also has a fixed contact 66 which is connected toa load, comprising a resistor 68 parallel therewith, both beinggrounded.

Turning now to FIG. 3, attention is directed first to the lower centerportion of the figure whereat is the switch 58 for pedal drum keying,along with the associated circuit elements. From the junction 62 a wire77 leads to a resistor 74. The resistor is connected through a capacitor76 to a normally open switch 78 which comprises a pedal drum on-offswitch operated by a suitable stop tablet on the organ.

The other side of the switch 78 is connected through a wire 80 to ajunction 82. The junction is directly connected to the base of an n-p-ntransistor 84. The junction is connected through a voltage dividerresistor 86 to ground, and the emitter also is connected to ground. Thejunction 82 also is connected to a second voltage divider resistor 88,and this resistor is connected to a positive voltage supply line 90.This line, in turn, is connected to a B-I- bus line 92, and this isconnected through a decoupling filter comprising a series resistor 94vand shunting capacitor 96 to a supply voltage indicated at +34 volts.

The collector of the transistor 84 is connected through a resistor 98 tothe positive voltage line 90, and it also is connected through a seriescapacitor 100 and resistor 102 to supply a positive pulse to a drumgenerator, indicated generally bythe numeral 104.

The drum generator is a phase shift oscillator biased short ofoscillation, and shock excited into decaying oscillation. The generator104 comprises a transistor 106 of the n-p-n type, having the emitterthereof grounded through a resistor 108 and parallel capacitor 110. The

base is shunted to ground through a resistor 112, and also is connectedto a capacitor 114. The capacitor 114 is connected to a grounded,shunting resistor 116, and to a capacitor 118. The capacitor 118 isreturned through ya capacitor 120 to the collector, and also isconnected to a resistor 122, leading to the line 124 from the resistor102. The resistor 122 also is connected to ground through a resistor126.

The collector of the transistor 106 is connected through a resisto-r 128to a positive voltage supply line 130 which is connected to the positive34 volts supply source through a decoupling filter comprising a seriesresistor 132 and shunting capacitor 134. The base of transistor 106 iSconnected to line 130 through a resistor.

The collector of the transistor 106 further is connected through aseries resistor 135 and capacitor 136 to a shunting capacitor 138, andhence to the moving contact 140 of a normal-full switch. In the lower ornormal position the movable contact 140 engages a fixed contact 142which is connected to the junction between a grounded resistor 144 and aseries resistor 146 leading to an output line 14S. The top of theresistor 146 is connected through a wire 150 to a second fixed contact152 alternatively engageable by the movable contact 40. In addition, thetop of the resistor 146 is connected by a wire 154 to a stop switch 156.With the stop switch in the lowered position shown, the output of thedrum generator is shortened to ground. When the switch is open, then theoutput is connected to the output line 148, and through a resistor 158to the upper stop tablet and filter assembly.

There is an additional output line 160 connected through a resistor 162to the lower stop tablet and filter assembly. There is aninterconnecting resistor 164 from the output line 148 to the lower stoptablet and filter assembly. In addition, from the output line 160 a line166 leads to a movable switch contact 168 which in the lowered positionshown engages a iixed contact connected to the top of a groundedresistor 170. The movable switch contacts 140 and 168 are gangedtogether as indicated at 172 for simultaneous movement. The wire 166also is connected to a movable switch contact 174 ganged at 176 with themovable Contact 156, and engageable with a grounded fixed contact.Movable switch contact 174 when in the closed position shown grounds theoutput of the output line 160, which carries signals hereinafter to bediscussed.

The switches 140, 168, as heretofore noted, comprise a normal-fullswitch. With the contacts in the lowered position, as controlled by asuitable stop tablet, the output is in normal position and at normalvolume. It will be appreciated that part of the output appearing on theline 160 is shunted to ground by the resistor 170, and that part of theinput to the switch 140v is shunted to ground through the resistor 144.On the other hand, when the movable switch contacts 140 and 168 are inraised position, the line 160 is no longer shunted to ground. At thesame time, the input to the switch contact 140 is connected at the topof the resistor 146 so that the shunting resistance to ground is muchgreater, and less of the signal is shunted.

Turning now to `the left central portion of FIG. 3, the circuit alsoincludes a noise generator generally designated by the numeral 178. Thenoise generator includes an n- -n transistor 180 connected as a diodewith its base being grounded and the emitter connected through aresistor 182 to the B+ supply indicated at -1-34 volts. Thediode-operated transistor is biased at its Zener point, and henceproduces a noise signal. The noise is of the type known as white noisewhich comprises a wide band, continuous spectrum output of substantiallyconstant amplitude. Preferably, a silicon transistor is selected for itsnoise output when biased to the Zener point, it being recognized thatsome transistors will put out more noise than others.

The output of the diode-connected transistor iS connected to the base ofan n-p-n transistor 184 through a capacitor 183, the input being shuntedby a capacitor 186 and a grounded resistor 188. The resistor 188 and thebase also are connected through a resistor 190 to the positive potentialline 92, the -resistors 190 and 188 acting as a voltage divider properlyto bias the base of the transistor 184. The emitter is connected to aresistor 192 paralleled by a capacitor 194, and both are connected toground by a resistor 196.

The collector of the transistor 184 is connected through a resistor 198to the positive potential line 92, and it also is connected by means of'a capacitor 200 to the base of a transistor 202, again of the n-p-ntype, the input being shunted to ground by a capacitor 204 and a voltagedividing resistor 206. The line 200 also is connected through a secondvoltage divider resistor 208 to the positive potential line 92. Theemitter of the transistor 202 is connected to ground through a resistor210 and parallel connected capacitor 212. As will be appreciated, thetwo transistors 184 and 202 comprise portions of amplifier stages toamplify the noise generated by the transistor 180.

The output of the collector of the transistor 202 is connected through acapacitor 214 to a junction 215 of a cymbal keyer 218. The cymbal keyercomprises a transistor 216 connected in a grounded base circuit with theemitter thereof connected through a capacitor 219 and series resistor220 to the junction 215. The cymbal keyer comprises an amplifying stagewhich is normally biased 01T. The junction 222 which is connected to thecollector of the transistor 216 is between a pair of voltage dividerbiasing resistors. One of these resistors 224 is connected to ground,While the other 226 is connected to the positive potential line 92.

Also connected to the potential line 92 is a resistor 228 which leads toa junction 230. The junction 230 is connected to a resistor 232, andthis in turn is connected to a junction 234 leading through a resistor236 to the emitter of the n-p-n transistor 216. The junction 230 also isconnected to a junction 238 which is grounded through a series connectedresistor 240 and capacitor 242. The junction 238 is connected by a wire244 to a junction 246, and this in turn is connected to a normally openswitch 248, comprising an on-off switch for the pedal cymbal keying. Theother side of the switch 248 is connected to the bail switch 54, 56described heretofore. With the switch 248 closed, closure ot the switch54, 56 changes the bias on the transistor 216 so that it conducts, andremains conducting with the cymbal sound continuing as long as the bailswitch is held closed. Actually, insofar as the cymbal keyer 218 isconcerned, the signal output therefrom is still a noise signal whichdoes not exactly correspond to the cymbal tone.

The output of the cymbal keyer as taken from the junction 222 is coupledthrough a capacitor 250 and series connected resistor 252 to a junction254. This junction is connected to the base of another n-p-n transistor256. The base is biased by voltage divider resistors 258 connected tothe positive potential line 92, and 260 connected to ground. The emitteris grounded through a resistor 262 and a parallel capacitor 264, whilethe collector is connected to a junction 266, the junction beingconnected through a resistor 268 to the positive potential supply line92.

The output of the noise amplier 270, comprising the transistor 256 andrelated parts, is connected to a tuned lter. Specically the junction 266is connected through a capacitor 272 and series resistor 274 to ajunction 276. A coil or inductance 278 is connected from this junctionto ground, as is a capacitor 280 paralleling the inductance and forminga parallel resonant circuit therewith. The junction also is connectedthrough a series resistor 282 and a shunting capacitor 284 to an outputline 286. This output line' is connected to the previously mentionedoutput line 160. A

j In addition, there is a resistor 288 connected from the junctionbetween the resistor 282 and capacitor 284 to 'a junction 290 which isshunted to ground by a resistor 292. A series resistor 294 leads fromthe junction 290 to an output point leading to the upper stop tablet andiilter assembly independently of the line 160. As will be understood,the three outputs referred to heretofore to the stop tablet and lterassemblies are shown simply by a single line in FIG. 2 as leading fromthe rhythm generators to thel filters and stops. The particular filterand stop switching to the amplier is not of particular importance at thepresent time, and hence is not disclosed in detail.

A shimmer generator 296 is shown at the lower left corner of FIG. 3, andcomprises a phase shift oscillator including an n-p-n transistor 298.Thev emitter is grounded through a resistor 300 and a parallel capacitor302, while the base is connected to a junction 304 between a groundedvoltage divider resistor 306 and a second voltage divider resistor 308leading to a positive voltage line 310 which is connected by adecoupling filter, including a s'hunting capacitor 312 and a seriesresistor 314 to the positive voltage source indicated at +34 Volts. Thecollector of the transistor 298 is connected to a junction 316, and thisjunction is supplied with positive potential through a resistor 318connected to the line 310. The junction 316 also is connected through afeedback capacitor 320 to a phase shifting network comprising a shuntingresistor 322, a series capacitor 324, a second shunting resistor 326,and a second series capacitor 328 connected to the junction 304.

The output of the shimmer generator, which oscillates at 17.5 cycles persecond plus or minus is taken from the junction 316 through a seriescapacitor 330, across a shunting capacitor 332, and through a seriesresistor 334 to the junction 234 of the cymbal keyer 218. The shimmergenerator amplitude modulates the noise input to the cymbal keyer. Thus,the output from the noise amplifier 270 as filtered by the parallelresonant circuit 278, 280 comprises a selected band of audio frequencieswhich is amplitude modulated at the frequency of the shimmer generator.The resulting output resembles the sound from a struck cymbal to an eX-tremely marked extent. The resonant frequency of the parallel resonantcircuit is on the order of 8 kilocycles.

Referring now to the upper left corner of FIG. 3, the pulse producer 30will be seen. It will be understood that the pulse producer includesmeans connected with the key switches Ifor producing a negative pulsewhenever a percussion tone is played. Such pulses from the upper manualare connected by means of a wire 336 to a diode 338, poled as shown, andparalleled by a resistor 340. The parallel combination of the diode andresistor are connected through la normally open upper manual stop tablet342 to a junction 344.

Similarly, the pulse producer lower manual is connected by a wire 346 toa lower manual stop tablet 348, which is normally open, and this stoptablet switch is connected to-the junction 344. It will be apparent thatthe diode 338 isprovided for isolation between the upper and lowermanual percussion switches.

The junction 344 is connected by a wire or line 350 and a seriescapacitor 352 to the junction 246 of the pedal cymbal switch 248, on theright or high side of the switch. This provides for an initialpercussive or crash cymbal sound. The subsequent sizzle is produced bythe circuitry previously described.

The junction 344 also is connected to a junction 354 of a transistorbiasing network comprising a grounded resistor 356 and a resistor 358.The top of the resistor 358 is connected to a positive line 360, andthis is `connected by a wire 362 to the B-j-bus line 92. The junction354 is connected to the base of an n-p-n transistor 364, the

6 emitter of which is grounded. The collector is connected by a resistor366 to the line 360.

The output of the transistor, which comprises a preamplifier, isconnected to the input of a Schmitt trigger circuit identified generallyby the numeral 368. In particular, a capacitor 370 is connected to thecollector of the transistor 364, and the capacitor is in turn connectedto a resistor 372 leading to a line 374.

The Schmitt circuit comprises two interconnected transistors 376 and378. The line 374 is connected to the base of the transistor 376 and tothe collector of the transistor 378. A capacitor 37'9 is included in theline 374 for feedback of a time constant pulse. The line 374 also isconnected through a resistor 380 to the emitter of the transistor 376and to the emitter of the transistor 378. Both emitters are groundedthrough a common resistor 382. The collector of the transistor 376 isconnected through a resistor 384 to the line 360, While the collector ofthe transistor 378 is connected through a resistor 386 to the line 360.

In addition, the collector of the transistor 376 is connected by meansof a resistor 388 to the lbase of the transistor 378, and this base isgrounded through a resistor 390. The biasing is such that the transistor376 is normally turned off or nonconducting, while the transistor 378 isnormally turned on or conducting.

Upon application of a negative pulse from the pulse producer 30 to theinput of the pre-amplifier stage at 354, the transistor 376 ismomentarily turned on, with concomitant switching 01T of the transistor378. The circuit practically immediately reverts to its initialcondition with the transistor 376 off and the transistor 378 on. Thisproduces a negative pulse in the nature of a half square wave at thecollector of the transistor 37 6.

The negative pulse at the collector of the transistor 376 is taken offby means of a line 392 and through a capacitor 394 to the input junction396 of a time constant circuit.

The junction 396 is shunted to ground by a resistor 398, and is alsoconnected to a diode 400 polarized to conduct negative pulses from leftto right, but to block any positive pulses. The diode `400 is connectedto a junction 402 which is shunted to ground `by a capacitor 404. It isalso connected through a resistor `406 to a junction 408. This junctionis connected through a resistor 410 to the positive line 360, and alsois connected to the emitter of an n-p-n transistor 412. The base of thistransistor is grounded, and the collector is connected to a junction 414which is connected through a resistor 416 to the positive line 360. Thejunction also is connected to a grounded resistor `417, and to acapacitor y418 which in turn is connected to a resistor 420 leading tothe junction 254 at the input of the noise amplifier 270.

The junction 408 is connected by a series capacitor 422, shunted by agrounded resistor 424, and in series with a resistor 426 leading to thejunction 215 at the input to the cymbal keyer.

The transistor 412 and the associated time constant circuit to the leftthereof comprise a brush keyer designated as 428. The brush keyer isnormally olf (i.e. the transistor 412 is off) and upon application of anegative pulse to the junction 396, the transistor is turned on. Itholds on for awhile due to the time constant circuit comprisingresistors 398 and 406, and 'capacitors 404 and 422.

The output from the noise generator 178 is connected through theresistor 426 to the input of the transistor 412, which acts in thenature of a gate. The pulse from the Schmitt trigger circuit turns thisgate on for the length of the pulse, plus some decay time as determinedby the time constant circuit. It will be appreciated that the pulse fromthe Schmitt trigger circuit is broader than the output pulse of thepulse producer 30 and of completely controllable quality. The noise, aspassed through the brush keyer 428, is applied by means of thecapacit-or 418 and resistor 420 to the input of the noiseamplier 270.

When a pulse is produced from the pulse producer 30 lby playing oneither the upper or the lower manual with t-he appropriate stop tabletor stop tablets 342, 348 closed, the Schmitt trigger circuit 368 startsthe brush noise envelope by turning `on the brush keyer 428. The timeconstant of the brush keyer determines the decay characteristics,although it is to be borne in mind that the decay is overcome by anyadditional pulse or pulses from the pulse producer 30 and consequentre-triggering of the brush keyer.

When the pedal cymbal stop switch 248 is closed, closing of the bail.switch 54, 56 will render the cymbal keyer 218 effective. This keyer isrelatively slow to turn on, and to provide a desirable crash attack, thebrush keyer is also turned on. There is a voltage drop upon closing ofthe switch 54, .56 which is coupled as a negative pulse throughcapacitor 352 and line 350 to the input of the Schmitt trigger circuit.Thus, the brush sound is keyed each time the cymbal is played, and thebrush fills in the attack crash noise. The cymbal keyer 218 then takesover shimmers the noise signal. The cymbal tone continues as long as theswitch 54, 56 is held closed, and decays according to a time constantdetermined by capacitors 242 :and 2'19 and resistors 240, 228, 232 and236. Re-triggering of the cymbal keyer starts a new cymbal sound as withthe brush keyer.

From the foregoing it will be apparent that with the proper stopswitches closed, a bass drum can be played as accompaniment to the pedalnotes of an electronic organ. The stop tablets for the pedal tonesthemselves can be in off position, whereby only the drum signal willcome through without the normal pedal tones. Preferably, the drumgenerator is set for a frequency of 68 to 75 cycles per second. Inaddition, a crash or sizzle cymbal can be produced along with or insteadofthe pedal notes, and the brush cymbal sound can be produced along withthe tones as played on the upper or lower manuals.

The specific example of the invention as herein shown and described isfor illustrative purposes only. Various changes in structure will nodoubt .occur to those skilled in the art, and will be understood asforming a part of the present invention insofar as they fall within thespirit and scope of the appended claims.

The invention is claimed as follows:

1. An electronic musical instrument comprising a plurality of tonegenerators for producing electronic oscillations corresponding tomusical tones, a plurality of keys and a plurality of pedals, aplurality of switches respectively selectively operable thereby,ampliier means, a plurality of filters and stops, said switches and saidfilters and stops respectively selectively interconnecting said tonegenerators and said amplifier means, electroacoustic transducing meansconnected to said amplifier means for converting the amplifiedelectronic oscillations into sound, and means for adding a cymbal toneupon operation of certain of said switches and certain of said stops andcomprising an electronic noise generator, a first normally closedelectronic gate connected to said noise generator, a second normallyclosed electronic gate connected to said noise generator, meansconnecting said gates to said amplifier means, means operable as anincident to operation of any of said certain switches to open said firstgate for a predetermined short period of time, and means operable as anincident to operation of any of said certain switches to open saidsecond gate for a period of time longer than said predetermined time toproduce a crash plus sizzle cymbal tone.

2. An electronic musical instrument comprising a plurality of tonegenerators for producing electronic oscillations corresponding tomusical tones, a plurality of keys and a plurality of pedals, aplurality of switches respectively selectively operable thereby,amplifier means, a plurality of filters and stops, said switches andsaid filtersand stops respectively selectively interconnecting said tonegenerators and said amplifier means, electroacoustic transducing meansconnected to said amplifier means for converting the amplifiedelectrical oscillations into sound, and means for adding a cymbal toneupon operation of certain of said switches and certain of said stops andcomprising an electronic noise generator, a first normally closedelectronic gate connected to said noise generator, a second normallyclosed electronic gate connected to said noise generator, a tunedcircuit connected to said first and second electronic gates and to saidamplifier means for passing a predetermined range of noise frequenciesfrom said gates to said amplifier means, means operable as an incidentto operation of any of said certain switches to open said first gate fora predetermined short period of time, and means operable as an incidentto operation of any of said certain switches to open said second gatefor a period of time longer than said predetermined time to produce acrash plus sizzle cymbal tone.

3. An electronic musical instrument as set forth in claim 2 and furtherincluding time delay means for producing a decay on the hold open timeof said second electronic gate.

4. An electronic musical instrument as set forth in claim 2 wherein themeans to open said second gate comprises a one-shot trigger circuit.

5. An electronic musical instrument comprising a plurality of tonegenerators for producing electronic oscillations corresponding tomusical tones, a plurality of keys and a plurality of pedals, aplurality of switches respectively selectively operable thereby,amplifier means, a plurality of lters and stops, said switches :and saidfilters and stops respectively selectively interconnecting said tonegenerators and said amplifier means, electroacoustic transducing meansconnected to said amplifier means for converting the :amplifiedelectronic oscillations into sound, and means for adding a cymbal toneupon operation of certain of said switches and certain of said stops andcomprising an electronic noise generator, a first normally closedelectronic gate connected to said noise generator, a second normallyclosed electronic gate connected to said noise generator, a shimmergenerator for producing electronic oscillations not higher than lowaudio frequency, means connecting said shimmer generator to said firstgate for amplitude modulating the electronic noise signal passed by saidgate, a tuned circuit connected to said first and second electronicgates and to said amplifier means for passing a predetermined range ofnoise frequencies from said gates to said amplifier means, meansoperable as an incident to operation of any of said certain switches toopen said second gate for a predetermined short period of time, andmeans operable as an incident to operation of any of said certainswitches to open said first gate for a period of time longer than saidpredetermined time to produce a crash plus Sizzle cymbal tone.

6. An electronic musical instrument as set forth in claim 5 and furtherincluding independent means interconnected with said first gate andoperable as an incident to operation of certain others of said switchesto open said second gate independent of opening of said first gate toproduce a crash cymbal tone.

7. An electronic musical instrument as set forth in claim 6 and furtherincluding an electronic drum oscillator normally biased off, and meansoperable as an incident to selective operation of selected ones of saidswitches to bias said drum oscillator into decaying oscillation, saiddrum oscillator being selectively connected to said amplifier means.

8. An electronic musical instrument comprising a plurality of tonegenerators for producing electronic oscillations corresponding tomusical tones, a plurality of keys and a plurality of pedals, aplurality of switches respectively selectively operated thereby,amplifier means, a plurality of filters and stops, said switches andsaid filters and stops respectively selectively interconnecting saidtone generators and said amplifier means, electroacoustic transducingmeans connected to said amplifier means for con- J verting the amplifiedelectronic oscillations into sound,

and means for adding a cymbal tone upon operation ofcertain of saidswitches and certain of said stops and comprising an electronic noisegenerator, said electronic noise generator comprising a transistorbiased to its zener point, a normally closed electronic gate connectedto said noise generator, means connecting said gate to said amplitiermeans for passing noise frequencies from said gate to said amplifiermeans, and means operable as an incident to operation of any of saidcertain switches to open said gate for a predetermined period of time toproduce a cymbal tone.

9. An electronic musical instrument comprising a plurality of tonegenerators for producing electronic oscillations corresponding tomusical tones, a plurality of keys and a plurality of pedals, aplurality of switches respectively selectively operable thereby,amplifier means, a plurality of filters and stops, said lswitches andsaid filters and stops respectively selectively interconnecting saidtone generators and said amplifier means, electroacoustic transducingmeans connected to said amplifier means for converting the amplifiedelectronic oscillations into sound, and means for adding a cymbal -toneupon operation of certain of said switches and certain of said stops andcornprising an electronic noise generator, a normally closed electronicgate connected to -said noise generator, means connecting saidelectronic gate to said amplifier means for passing a noise signal fromsaid gate to said amplier means, a one-shot trigger circuit connected tosaid gate for opening said gate for a predetermined period of time toproduce a cymbal tone, and means connected to said one-shot triggercircuit and operable as an incident to operation of any of said certainswitches to cause said trigger circuit to operate to produce a pulse toopen said gate for said predetermined period of time.

10. In an electronic musical instrument, means for producing a widespectrum sound comprising an electronic noise source, said noise sourceincluding a transistor having base, emitter and collector elements, asource of electric potential, means connecting said source to two ofsaid transistor elements to bias said transistor to its Zener point,amplifier means, means interconnecting said two elements with saidamplifier means, electroacoustic transducing means for convertingelectrical signals into audible sound, and means interconnecting saidamplifier means and said transducing means.

No references cited.

ARTHUR GAUSS, Primary Examiner. I. A. JORDAN, Assistant Examiner.

1. AN ELECTRONIC MUSICAL INSTRUMENT COMPRISING A PLURALITY OF TONEGENERATORS FOR PRODUCING ELECTRONIC OSCILLATIONS CORRESPONDING TOMUSICAL TONES, A PLURALITY OF KEYS AND A PLURALITY OF PEDALS, APLURALITY OF SWITCHES RESPECTIVELY SELECTIVELY OPERABLE THEREBY,AMPLIFIER MEANS, A PLURALITY OF FILTERS AND STOPS, AND SWITCHES AND SAIDFILTERS AND STOPS RESPECTIVELY SELECTIVELY INTERCONNECTING SAID TONEGENERATORS AND SAID AMPLIFIER MEANS, ELECTROACOUSTIC TRANSDUCING MEANSCONNECTED TO SAID AMPLIFIER MEANS FOR CONVERTING THE AMPLIFIEDELECTRONIC OSCILLATIONS INTO SOUND, AND MEANS FOR ADDING A CYMBAL TONEUPON OPERATION OF CERTAIN OF SAID SWITCHES AND CERTAIN OF SAID STOPS ANDCOMPRISING AN ELECTRONIC NOISE GENERATOR, A FIRST NORMALLY CLOSEDELECTRONIC GATE CONNECTED TO SAID NOISE GENERATOR, A SECOND NORMALLYCLOSED ELECTRONIC GATE CONNECTED TO SAID NOISE GENERATOR, MEANSCONNECTING SAID GATES TO SAID AMPLIFIER MEANS, MEANS OPERABLE AS ANINCIDENT TO OPERATION OF ANY OF SAID CERTAIN SWITCHES TO OPEN AND FIRSTGATE FOR A PREDETERMINED SHORT PERIOD OF TIME, AND MEANS OPERABLE AS ANINCIDENT TO OPERATION OF ANY OF SAID CERTAIN SWITCHES TO OPEN SAIDSECOND GATE FOR A PERIOD OF TIME LONGER THAN SAID PREDETERMINED TIME TOPRODUCE A CRASH PLUS SIZZLE CYMBAL TONE.